No, e.g. Manu samhita 10.115 allows lending at interest as one of seven lawful modes of acquiring property. The amount of the interest isn't specified there.
On a related note, 8.398 specifies tax for the king as 5%. Compare with today's taxes...

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A money-lender may stipulate as an increase of his capital, for the interest, allowed by Vasishtha, and take monthly the eightieth part of a hundred.
Or, remembering the duty of good men, he may take two in the hundred (by the month), for he who takes two in the hundred becomes not a sinner for gain.
Just two in the hundred, three, four, and five (and not more), he may take as monthly interest according to the order of the castes (varna).
But if a beneficial pledge (i.e. one from which profit accrues, has been given), he shall receive no interest on the loan; nor can he, after keeping (such) a pledge for a very long time, give or sell it.
A pledge (to be kept only) must not be used by force, (the creditor), so using it, shall give up his (whole) interest, or, (if it has been spoilt by use) he shall satisfy the (owner) by (paying its) original price; else he commits a theft of the pledge.
Neither a pledge nor a deposit can be lost by lapse of time; they are both recoverable, though they have remained long (with the bailee).
Stipulated interest beyond the legal rate, being against (the law), cannot be recovered; they call that a usurious way (of lending); (the lender) is (in no case) entitled to (more than) five in the hundred. (Manu 8.140-145,152)

To invest money on interest, to be a jeweller, to tend
cattle, tillage and trade, - these are declared as occupations
for the Vaisya caste. (Parasara smrti 1.63)

Parasara 1.24 specifies dharmasastras for specific yugas:
For the Krita are suited the laws of Manu; for the Treta, those
by Gautama (are) prescribed; for the Dvapara those by Shanka and
Likhita; for the Kali, those by Parasara are prescribed.)

Agriculture and trade (are) also (lawful for a Brahmana) provided he does not do the work himself,
Likewise lending money at interest.
The additional (occupations) of a Vaisya are, agriculture, trade, tending cattle, and lending money at interest.
The legal interest for money lent (is at the rate of) five Mashas a month for twenty (Karshapanas). (Gautama dharma sutra 10.5-6,49, 12.29)
[Manu VIII, 140; Yajnavalkya II, 37; Colebrooke I, Digest 25. Haradatta states that a Karshapana contains twenty Mishas. Thus the monthly interest for 400 Mashas being five Mashas, the rate is 1 per cent for the month, or 15 per cent per annum.]

For a Vaisya, tillage, keeping cows (and other cattle), traffic, lending money upon interest, and growing seeds.
(As regards the interest to be paid), he shall take in the direct order of the castes two, three, four, or five in the hundred by the month (if no pledge has been given).
Or let debtors of any caste pay as much interest as has been promised by themselves.
After the lapse of one year let them pay interest according to the above rule, even though it have not been agreed on.
By the use of a pledge (to be kept only) interest is forfeited. (Visnu smriti 2.13, 6.2-5)

Where there is a pledge, the interest, month by month, shall be an eightieth part; otherwise, two, three, four or five parts, in a hundred, according to the order of cast.
They however who travel in forests give ten parts; they who go to sea, twenty parts, in a hundred. Or, all must render to all, of whatever cast, the rate of interest settled amongst themselves. (Yajnavalkya smriti 2.37-38)